Rivers and lakes

The alligator gar is a large North American fish with a broad, tooth-filled snout.

The American alligator is a freshwater crocodilian of the southeastern United States.

Arapaimas are large South American freshwater fishes.

The Argentine horned frog is a broad-bodied ambush hunter with a very large mouth.

The Atlantic salmon hatches in a river, grows up at sea, and returns to the same river to spawn.

Avocets are long-legged wading birds with upward-curving bills.

The axolotl is a salamander that never grows up.

The bald eagle is the national bird of the United States.

Basilisks are tropical American lizards.

Bats include many different feeding and roosting specialists.

Beavers are semiaquatic rodents that alter waterways.

The beluga whale is a white toothed whale of Arctic and sub-Arctic seas.

Betta splendens is a small Southeast Asian freshwater fish.

The black kite is a medium-sized raptor with angled wings and a forked tail.

The black swan is a large Australian waterbird with black plumage, white flight feathers and a bright red bill.

The bull shark is a robust coastal shark that can also spend time in fresh water.

The American bullfrog is a large frog that waits near water for passing prey.

The Burmese python is a large Asian constrictor with dark blotches.

Caecilians are limbless amphibians with concealed eyes and sensory tentacles.

Caimans are crocodilians of the Americas.

The Canada goose is a large black-necked goose with a white chinstrap, native to North America and now settled on four continents.

The capybara is the largest rodent in the world.

The Carolina parakeet was the only parrot native to the eastern United States.

Carp is a broad familiar name for related freshwater fishes.

Catfishes include many freshwater and marine species.

The cockatiel is the smallest cockatoo, and it lives across the dry inland of Australia.

The common frog is a widespread European amphibian that also occurs in northwestern Asia.

The common kingfisher is a small blue and orange bird of clear, slow rivers across Europe, Asia and North Africa.

The common loon is a heavy diving bird of northern lakes, with a black head, a white necklace and a dagger bill.

Cormorants are fish-eating diving birds.

The cottonmouth is a venomous, semiaquatic pit viper of the southeastern United States.

Crayfish are freshwater crustaceans.

Damselflies link freshwater development with an aerial adult stage.

Daphnia are small freshwater crustaceans rather than fleas.

Discus are deep-bodied South American cichlids familiar in aquariums.

Dragonflies hunt both underwater and in the air.

Ducks are waterbirds with many different feeding habits.

Egrets are herons known for pale plumage in several species.

The Egyptian goose is a pale brown waterbird of African rivers, lakes and grassland, marked by a dark ring around each eye.

The electric eel is a South American freshwater fish that generates electrical signals.

The European polecat is a dark, stocky mustelid with a pale face mask that hunts frogs, voles and rabbits by night.

The fire salamander is a dark European amphibian marked with yellow or orange.

Flatworms include many unrelated-looking forms.

Flounders are flattened fishes adapted to life near the bottom.

The gharial is a crocodilian with an exceptionally long narrow snout.

Chinese giant salamanders are large aquatic amphibians with broad heads and flattened bodies.

Glass frogs are small tree-dwelling amphibians with translucent undersides.

The goldfish is a domesticated freshwater fish with many selectively bred forms.

The goliath frog is an exceptionally large frog of equatorial African rivers.

The great blue heron is the biggest of the North American herons and a patient hunter of shallow water.

The great egret is a tall white heron that hunts fish in shallow water on six continents.

The green anaconda is a heavy-bodied South American boa associated with slow-moving water.

The grey heron is a tall grey and white wading bird of European, Asian and African wetlands.

The guppy is a small freshwater fish widely bred for aquariums.

The hellbender is a large aquatic salamander of eastern and central North America.

Herons are long-legged waterbirds.

The hippopotamus spends its days in rivers and lakes and its nights grazing on land.

The hoatzin is a crested bird of Amazon swamp forest that lives on leaves and ferments them in a huge crop.

The jaguar is the largest cat in the Americas and the third largest in the world.

The Japanese giant salamander spends its life in cool flowing streams.